There's more to it than 'electronics'.
Here's my more recent fixes:
-----------------------------------
1. The fuel pipe saga.
Fuel pipe from pump (tank) to engine is a single, molded, hard-plastic and inflexible pipe. Connecting it to new quick release attachments on either end requires a heat gun. At the factory they can heat-shrink the connectors onto the pipes as there is no fuel in the car.
When my quick-release snapped off[1] while I was replacing the fuel pump, dealer quoted my ZAR17,500 for a replacement pipe. To actually install it would require removing everything under the car because it is inflexible and molded to the shape of the car.
Older cars had less efficient (i.e. thicker OD pipes with the same ID) fuel pipes, but they were flexible and easy to route. They used standard clamps which are available for cents right now. The advantage of the newer pipes is that:
a) Cheaper to install (done by robots), and
b) With the quick release joiner, easy for a robot to snap on the connections on either end.
With the older, cheaper and repairable flexible pipes, the manufacturing process required a human. The more expensive pipes result in a cheaper-to-assemble car, even if the BOM is higher.
-----------------------------------
2. Heater blower motor refusing to come on.
The AC units (including heater and blower motor) are controlled by low-current signals. This lets the unit have a rotary encoder when the human wants to adjust blower speed manually while still allowing the microcontroller to adjust blower speed when the user simply sets a target temperature.
This requires an additional current-splitter to limit the current to the blower motor (controlling the speed) while maintaining the voltage. When the blower is spinning at a low speed current is dumped into a heat sink and the blower gets very little current. At high speed no current needs to be dumped and the blower can spin at full speed.
My current limiter melted. This required a manufacturer-only replacement, as the digital signals controlling it are completely opaque to the technician (me) fixing the car.[2] Older cars without the rotary encoder had physical switches that switched the blower motor between one of 5 output speeds. Anything in the older system that broke can be replaced by standard switches and relays.
Anything, even the smallest component, in the newer HVAC system that breaks means you have to hope like hell that the manufacturer is still making parts for the car.
In this scenario, a 1995 mid-range car is going to outlive a 2025 mid-range sedan.
-----------------------------------
3. Engine and transmissions!
This is the big one: a 2015 car that, after 20 years, has a worn out slushbox, might have to be thrown away! Why? Because if you are unable to replace the clutches and springs and other parts inside the slushbox due to lack of parts availability, you can't simply swap in a new one, or replace it with a manual - the car is going to throw up a dozen diagnostic codes and probably won't even start.
That 1995 mid-range car? The engine and transmission are not coded to work with each other only. Swap in a Toyota v6 engine+transmission into a broke-ass Ford? Sure, why not?
Same with the radio. In older cars the radio was a swappable unit with standard sizes. In new cars the infotainment system is rarely a regular shape, and in those cars where it is nothing but a screen, it's still hooked into the CAN bus to deliver warnings!
You can upgrade your 1995 mid-range car to use the latest in infotainment technology (maps, voice commands, etc) by simply buying a head unit off Amazon. You cannot upgrade your top-off-the-range Range Rover, Mercedes Benz or Audi just 4 years after purchase!
-----------------------------------
My point is this: the older cars can, with simple mechanical and electro-mechanical non-manufacturer parts, effectively run until humanity just doesn't have fuel anymore. The newer cars will, once the manufacturer stops producing parts for them, have to be scrapped.
There is little incentive for the manufacturer to continue producing parts for a 10-year old car, and that gets even smaller as the car ages.
In fact, I completely expect, as time goes on, that manufacturers would (if they haven't started already) code each component to the VIN or secret key so that parts from a breakers yard won't run in any other car even if it's the same model.
Their preference is: When the radio breaks, it's time to buy a new car or live without a radio.
--------------------
[1] Plastic that over time got brittle.
[2] With a lot of work and lugging my ancient 'scope to the car, I could have worked out what signals were being sent (if digital; analogue would have been easier of course, requiring only a multimeter), designed a circuit around a MOSFET or similar and used a tiny microcontroller to read the signals and control the current.